Mobile phone SIMs can go to hell and back

Can survive temperatures up to 450°C & more, say researchers

Even if your mobile phone is unlikely to survive a fire, chances are that the SIM card inside might.

Scientists have discovered that some SIM cards can withstand heat up to 450°C and possibly even higher. The discovery should be useful for police and forensics staff investigating terror attacks and other crimes.

Hot technology

A total of 12 SIM cards were subjected to heat trials by electronic engineers Benjamin Jones and Tony Kenyon from University College London, AFP reports. The researchers tried to recover data from the SIM cards by attaching tiny probes to the circuit and reading its contents via an interface pad.

Six cards were heated to around 180°C and could be read after rewiring with no loss of data. Five were cooked to 450°C, four of which could not be read by the researchers. However, the fifth one could, albeit briefly. The twelfth, heated to 650°C, could not be read.

Jones and Kenyon said that the experiment proves SIM cards can survive in temperatures up to 450°C - and "quite possibly beyond that".

In an article published in the latest issue of Forensic Science International, the researchers pointed out that the rewiring technique they used was not the last resort for forensic experts wanting to delve into a damaged SIM card.

Reading data

"A chip that has been exposed to such temperatures may also be mechanically damaged, and the data may not be retrieved by simple probing or rewiring. But the data itself remains uncompromised and can possibly be read using other techniques," Jones and Kenyon said.

SIM cards may also survive for much longer in a blaze if they are close to the floor or on a desk, as temperatures in a building fire vary greatly according to the location.

Information stored on the SIM card - including records of numbers received, numbers dialled and text messages - could prove vital when investigating crimes. After the 2004 Madrid train bombings, for example, investigators were able to made arrests after recovering SIM cards from the phones that were intended to trigger two unexploded bombs.